#include "../server.hpp"

#define DEFAULT_TIMEOUT 30

std::unordered_map<std::string, std::string> _mime_msg = {
    {".aac", "audio/aac"},
    {".abw", "application/x-abiword"},
    {".arc", "application/x-freearc"},
    {".avi", "video/x-msvideo"},
    {".azw", "application/vnd.amazon.ebook"},
    {".bin", "application/octet-stream"},
    {".bmp", "image/bmp"},
    {".bz", "application/x-bzip"},
    {".bz2", "application/x-bzip2"},
    {".csh", "application/x-csh"},
    {".css", "text/css"},
    {".csv", "text/csv"},
    {".doc", "application/msword"},
    {".docx", "application/vnd.openxmlformatsofficedocument.wordprocessingml.document"},
    {".eot", "application/vnd.ms-fontobject"},
    {".epub", "application/epub+zip"},
    {".gif", "image/gif"},
    {".htm", "text/html"},
    {".html", "text/html"},
    {".ico", "image/vnd.microsoft.icon"},
    {".ics", "text/calendar"},
    {".jar", "application/java-archive"},
    {".jpeg", "image/jpeg"},
    {".jpg", "image/jpeg"},
    {".js", "text/javascript"},
    {".json", "application/json"},
    {".jsonld", "application/ld+json"},
    {".mid", "audio/midi"},
    {".midi", "audio/x-midi"},
    {".mjs", "text/javascript"},
    {".mp3", "audio/mpeg"},
    {".mpeg", "video/mpeg"},
    {".mpkg", "application/vnd.apple.installer+xml"},
    {".odp", "application/vnd.oasis.opendocument.presentation"},
    {".ods", "application/vnd.oasis.opendocument.spreadsheet"},
    {".odt", "application/vnd.oasis.opendocument.text"},
    {".oga", "audio/ogg"},
    {".ogv", "video/ogg"},
    {".ogx", "application/ogg"},
    {".otf", "font/otf"},
    {".png", "image/png"},
    {".pdf", "application/pdf"},
    {".ppt", "application/vnd.ms-powerpoint"},
    {".pptx", "application/vnd.openxmlformatsofficedocument.presentationml.presentation"},
    {".rar", "application/x-rar-compressed"},
    {".rtf", "application/rtf"},
    {".sh", "application/x-sh"},
    {".svg", "image/svg+xml"},
    {".swf", "application/x-shockwave-flash"},
    {".tar", "application/x-tar"},
    {".tif", "image/tiff"},
    {".tiff", "image/tiff"},
    {".ttf", "font/ttf"},
    {".txt", "text/plain"},
    {".vsd", "application/vnd.visio"},
    {".wav", "audio/wav"},
    {".weba", "audio/webm"},
    {".webm", "video/webm"},
    {".webp", "image/webp"},
    {".woff", "font/woff"},
    {".woff2", "font/woff2"},
    {".xhtml", "application/xhtml+xml"},
    {".xls", "application/vnd.ms-excel"},
    {".xlsx", "application/vnd.openxmlformatsofficedocument.spreadsheetml.sheet"},
    {".xml", "application/xml"},
    {".xul", "application/vnd.mozilla.xul+xml"},
    {".zip", "application/zip"},
    {".3gp", "video/3gpp"},
    {".3g2", "video/3gpp2"},
    {".7z", "application/x-7z-compressed"}
};
std::unordered_map<int, std::string> _statu_msg = {
    {100, "Continue"},
    {101, "Switching Protocol"},
    {102, "Processing"},
    {103, "Early Hints"},
    {200, "OK"},
    {201, "Created"},
    {202, "Accepted"},
    {203, "Non-Authoritative Information"},
    {204, "No Content"},
    {205, "Reset Content"},
    {206, "Partial Content"},
    {207, "Multi-Status"},
    {208, "Already Reported"},
    {226, "IM Used"},
    {300, "Multiple Choice"},
    {301, "Moved Permanently"},
    {302, "Found"},
    {303, "See Other"},
    {304, "Not Modified"},
    {305, "Use Proxy"},
    {306, "unused"},
    {307, "Temporary Redirect"},
    {308, "Permanent Redirect"},
    {400, "Bad Request"},
    {401, "Unauthorized"},
    {402, "Payment Required"},
    {403, "Forbidden"},
    {404, "Not Found"},
    {405, "Method Not Allowed"},
    {406, "Not Acceptable"},
    {407, "Proxy Authentication Required"},
    {408, "Request Timeout"},
    {409, "Conflict"},
    {410, "Gone"},
    {411, "Length Required"},
    {412, "Precondition Failed"},
    {413, "Payload Too Large"},
    {414, "URI Too Long"},
    {415, "Unsupported Media Type"},
    {416, "Range Not Satisfiable"},
    {417, "Expectation Failed"},
    {418, "I'm a teapot"},
    {421, "Misdirected Request"},
    {422, "Unprocessable Entity"},
    {423, "Locked"},
    {424, "Failed Dependency"},
    {425, "Too Early"},
    {426, "Upgrade Required"},
    {428, "Precondition Required"},
    {429, "Too Many Requests"},
    {431, "Request Header Fields Too Large"},
    {451, "Unavailable For Legal Reasons"},
    {501, "Not Implemented"},
    {502, "Bad Gateway"},
    {503, "Service Unavailable"},
    {504, "Gateway Timeout"},
    {505, "HTTP Version Not Supported"},
    {506, "Variant Also Negotiates"},
    {507, "Insufficient Storage"},
    {508, "Loop Detected"},
    {510, "Not Extended"},
    {511, "Network Authentication Required"}
};


class Util {
public:
    //字符串分割函数：将src字符串按照sep进行分割，得到各个字符放到array中，最终返回子串的数量
    //字符串分割函数,将src字符串按照sep字符进行分割，得到的各个字串放到arry中，最终返回字串的数量
        static size_t Split(const std::string &src, const std::string &sep, std::vector<std::string> *arry) {
            size_t offset = 0;
            // 有10个字符，offset是查找的起始位置，范围应该是0~9，offset==10就代表已经越界了
            while(offset < src.size()) {
                size_t pos = src.find(sep, offset);//在src字符串偏移量offset处，开始向后查找sep字符/字串，返回查找到的位置
                if (pos == std::string::npos) {//没有找到特定的字符
                    //将剩余的部分当作一个字串，放入arry中
                    if(pos == src.size()) break;
                    arry->push_back(src.substr(offset));
                    return arry->size();
                }
                if (pos == offset) {
                    offset = pos + sep.size();
                    continue;//当前字串是一个空的，没有内容
                }
                arry->push_back(src.substr(offset, pos - offset));
                offset = pos + sep.size();
            }
            return arry->size();
        }
    //读取文件内容：将读取的内容放到一个Buffer中
    static bool ReadFile(const std::string& filename, std::string* buf) {
        std::ifstream ifs(filename, std::ios::binary);
        if(ifs.is_open() == false) {
            ERR_LOG("OPEN %s FILE FALIED", filename.c_str());
            return false;
        }
        size_t fsize = 0;
        ifs.seekg(0, ifs.end);//跳转读写位置到末尾
        fsize = ifs.tellg();//获取当前读写位置相对于起始位置的偏移量，从末尾偏移刚好就是文件大小
        ifs.seekg(0, ifs.beg);//跳转到起始位置
        buf->resize(fsize);//开辟文件大小的空间
        ifs.read(&(*buf)[0], fsize);
        if (ifs.good() == false) {
            ERR_LOG("READ %s FILE FALIED!", filename.c_str());
            ifs.close();
            return false;
        }
        ifs.close();
        return true;
    }
    //向文件写入内容
    static bool WriteFile(const std::string& filename, std::string& buf) {
        std::ofstream ofs(filename, std::ios::binary | std::ios::trunc);
        if (ofs.is_open() == false) {
            ERR_LOG("OPEN %s FILE FALIED", filename.c_str());
            return false;
        }
        ofs.write(buf.c_str(), buf.size());
        if (ofs.good() == false) {
            ERR_LOG("WRITE %s FILE FALIED", filename.c_str());
            ofs.close();
            return false;
        }
        ofs.close();
        return true;
    }
    //URL编码：避免URL中资源路径与查询字符串中的特殊字符与HTTP请求中特殊字符产生歧义
    //编码格式：将特殊字符的ASCII值转换为两个16进制字符，前缀%,例如 C++ -> C%2b%2b
    //不编码的特殊字符：RFC3986文档规定：. - _ ~字母，数字属于绝对不编码字符
    //RFC3986文档规定，编码格式 %HH
    //W3C文档规定，查询字符串中的空格必须被编码为+，解码则是+转空格
    static std::string UrlEncode(const std::string url, bool convert_space_to_plus) {
        std::string res;
        for (auto& ch : url) {
            if (ch == '.' || ch == '-' || ch == '_' || ch == '~' || isalnum(ch)) {
                res += ch;
                continue;
            }
            if (ch == ' ' && convert_space_to_plus == true) {
                res += '+';
                continue;
            }
            //剩下的字符都是需要编码的字符
            char tmp[4] = {0};
            snprintf(tmp, 4, "%%%02X", ch);
            res += tmp;
        }
        return res;
    }
    static char HEXTOI(char ch) {
        if (ch >= '0' && ch <= '9') {
            return ch - '0';
        }
        else if (ch >= 'a' && ch <= 'z') {
            return ch - 'a' + 10;
        }
        else if (ch >= 'A' && ch <= 'Z') {
            return ch - 'A' + 10;
        }
        else {
            return -1;
        }
    }
    //URL解码：遇到%把%后的2个字符转换为数字，第一个数字左移4位，然后加上第二个数字：+ -> 2b ：%2b -> 2 << 4 + 11
    static std::string UrlDecode(std::string url, bool convert_space_to_plus) {
        std::string res;
        for(int i = 0; i < url.size(); i++) {
            if (url[i] == '+' && convert_space_to_plus == true) {
                res += ' ';
                continue;
            }
            if (url[i] == '%' && (i + 2) < url.size()) {
                char v1 = HEXTOI(url[i+1]);
                char v2 = HEXTOI(url[i+2]);
                char v = v1 * 16 + v2;
                res += v;
                i += 2;
                continue;
            }
            res += url[i];
        }
        return res;
    }
    //响应状态码的描述信息获取：
    static std::string StatuDesc(int statu) {
        
        auto it = _statu_msg.find(statu);
        if(it != _statu_msg.end()) {
            return it->second;
        }
        return "Unknow";
    }
    //根据文件后缀获取文件mime
    static std::string ExtMime(const std::string& filename) {
        
        size_t pos = filename.find_last_of('.');
        if (pos == std::string::npos) {
            return "application/octet-stream";
        }
        std::string ext = filename.substr(pos);
        auto it = _mime_msg.find(ext);
        if(it == _mime_msg.end()) {
            return "application/octet-stream";
        }
        return it->second;
    }
    //判断一个文件是否是一个目录
    static bool IsDirctory(const std::string& filename) {
        struct stat st;
        int ret = stat(filename.c_str(), &st);
        if (ret < 0) {
            return false;
        }
        return S_ISDIR(st.st_mode);
    }
    //判断一个文件是否是普通文件
    static bool IsRegular(const std::string& filename) {
        struct stat st;
        int ret = stat(filename.c_str(), &st);
        if (ret < 0) {
            return false;
        }
        return S_ISREG(st.st_mode);
    }
    //HTTP请求的资源路径有效性判断
    // /index.html --- 前边的/叫相对根目录，映射的是某个服务器上的子目录
    // 想表达的意思是。客户端只能请求相对根目录中的资源，其他地方的资源都不予理会
    // /../login，这个路径中的..会让路径的查找跑到相对根目录之外，这是不合理的不安全的
    static bool ValidPath(const std::string& path) {
        // 思想：计算目录深度：按照/进行路径分割，根据多少子目录，计算目录深度，有多少层，深度不能小于0
        std::vector<std::string> subdir;
        Split(path, "/", &subdir);
        int level = 0;
        for(auto& dir : subdir) {
            if (dir == "..") {
                level--;
                if (level < 0) return false;
                continue;
            }
            level++;
        }
        return true;
    }
};

class HttpRequest {
public:
    std::string _method;    //请求方法
    std::string _path;      //资源路径
    std::string _version;   //协议版本
    std::string _body;      //请求正文
    std::smatch _matches;   //资源路径的正则提取数据
    std::unordered_map<std::string, std::string> _headers;  //头部字段
    std::unordered_map<std::string, std::string> _params;   //查询字符串
public:
    HttpRequest():_version("HTTP/1.1") {}
    void ReSet() {
        _method.clear();
        _path.clear();
        _version = "HTTP/1.1";
        _body.clear();
        std::smatch match;
        _matches.swap(match);
        _headers.clear();
        _params.clear();
    }
    //插入头部字段
    void SetHeader(const std::string& key, const std::string& val) {
        _headers.insert(std::make_pair(key, val));
    }
    //判断是否存在指定的头部指针
    bool HasHeader(const std::string& key) const {
        auto it = _headers.find(key);
        if(it == _headers.end()) {
            return false;
        }
        return true;
    }
    //获取头部字段的值
    std::string GetHeader(const std::string& key) const {
        auto it = _headers.find(key);
        if(it == _headers.end()) {
            return "";
        }
        return it->second;
    }
    //插入查询字符串
    void SetParam(const std::string& key, const std::string& val) {
        _params.insert(std::make_pair(key, val));
    }
    //判断是否有某个指定的查询字符串
    bool HasParam(const std::string& key) const {
        auto it = _params.find(key);
        if(it == _params.end()) {
            return false;
        }
        return true;
    }
    //获取指定的查询字符串
    std::string GetParam(const std::string& key) const {
        auto it = _params.find(key);
        if(it == _params.end()) {
            return "";
        }
        return it->second;
    }
    //获取正文长度
    size_t ContentLength() const {
        bool ret = HasHeader("Content-Length");
        if (ret == false) {
            return 0;
        }
        std::string clen = GetHeader("Content-Length");
        return std::stol(clen);
    }
    //判断是否是短链接
    bool Close()  const {
        // 没有Connection字段，或者有Connection但是值是close，则都是短链接，否则就是长连接
        if (HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive") {
            return false;
        }
        return true;
    }
};

class HttpResponse {
public:
    int _statu;
    bool _redirect_flag;
    std::string _body;
    std::string _redirct_url;
    std::unordered_map<std::string, std::string> _headers;
public:
    HttpResponse():_redirect_flag(false), _statu(200) {}
    HttpResponse(int statu):_redirect_flag(false), _statu(statu) {}
    void ReSet() {
        _statu = 200;
        _redirect_flag = false;
        _body.clear();
        _redirct_url.clear();
        _headers.clear();
    }
    void SetHeader(const std::string& key, const std::string& val) {
        _headers.insert(std::make_pair(key, val));
    }
    bool HasHeader(const std::string& key) {
        auto it = _headers.find(key);
        if(it == _headers.end()) {
            return false;
        }
        return true;
    }
    std::string GetHeader(const std::string& key) {
        auto it = _headers.find(key);
        if(it == _headers.end()) {
            return "";
        }
        return it->second;
    }
    void SetContent(const std::string& body, const std::string& type = "text/html") {
        _body = body;
        SetHeader("Content-Type", type);
    }
    void SetRedirect(const std::string& url, int statu = 302) {
        _statu = statu;
        _redirect_flag = true;
        _redirct_url = url;
    }
    bool Close() {
        // 没有Connection字段，或者有Connection但是值是close，则都是短链接，否则就是长连接
        if (HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive") {
            return false;
        }
        return true;
    }
};

typedef enum {
    RECV_HTTP_ERROR,
    RECV_HTTP_LINE,
    RECV_HTTP_HEAD,
    RECV_HTTP_BODY,
    RECV_HTTP_OVER
}HttpRecvStatu;

#define MAX_LINE 8192
class HttpContext {
private:
    int _resp_statu;            //响应状态码
    HttpRecvStatu _recv_statu;  //当前接收及解析的阶段状态
    HttpRequest _request;       //已经解析得到的请求信息
private:
    bool ParseHttpLine(const std::string& line) {
        std::smatch matches;
        std::regex e("(GET|HEAD|POST|PUT|DELETE) ([^?]*)(?:\\?(.*))? (HTTP/1\\.[01])(?:\n|\r\n)?", std::regex::icase);
        bool ret = std::regex_match(line, matches, e);
        if (ret == false) {
            _recv_statu = RECV_HTTP_ERROR;
            _resp_statu = 400;//BAD REQUEST
            return false;
        }
        //请求方法的获取
        _request._method = matches[1];
        std::transform(_request._method.begin(), _request._method.end(), _request._method.begin(), ::toupper);
        //资源路径的获取
        _request._path = Util::UrlDecode(matches[2], false);
        //协议版本的获取
        _request._version = matches[4];
        //查询字符串的获取与处理
        std::vector<std::string> query_string_array;
        std::string query_string = matches[3];
        //查询字符串的格式，key=val&key=val...，先以&符号进行分割，得到各个字串
        Util::Split(query_string, "&", &query_string_array);
        //针对各个字串，以 = 符号分割，得到key，val，得到之后需要进行URL解码
        for(auto& ch : query_string_array) {
            size_t pos = ch.find("=");
            if (pos == std::string::npos) {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 400;//BAD REQUEST
                return false;
            }
            std::string key = Util::UrlDecode(ch.substr(0, pos), true);
            std::string val = Util::UrlDecode(ch.substr(pos+1), true);
            _request.SetParam(key, val);
        }
        //首行处理完毕，进入头部获取阶段
        return true;
    }
    bool RecvHttpLine(Buffer* buf) {
        if (_recv_statu != RECV_HTTP_LINE) return false;
        //1.获取一行数据
        std::string line = buf->GetLineAndPop();
        //2.考虑的一些要素：缓冲区的数据不足一行，获取的一行数据超级大
        if (line.size() == 0) {
            //缓冲区数据不足一行，需要判断缓冲区的可读数据长度，如果很长但不足一行，就是有问题的
            if (buf->ReadableSize() > MAX_LINE) {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414;//URI TOO LONG
                return false;
            }
            //缓冲区中不足一行，但是也不多，等待新数据到来
            return true;
        }
        if (line.size() > MAX_LINE) {
            _recv_statu = RECV_HTTP_ERROR;
            _resp_statu = 414;//URI TOO LONG
            return false;
        }
        bool ret = ParseHttpLine(line);
        if (ret == false) {
            return false;
        }
        _recv_statu = RECV_HTTP_HEAD;
        return true;
    }
    bool RecvHttpHead(Buffer* buf) {
        if (_recv_statu != RECV_HTTP_HEAD) return false;
        //一行一行取出数据，直到遇到空行为止，头部格式：key：val\r\nkey：val\r\n...
        while (1)
        {
             //1.获取一行数据
            std::string line = buf->GetLineAndPop();
            //2.考虑的一些要素：缓冲区的数据不足一行，获取的一行数据超级大
            if (line.size() == 0) {
                //缓冲区数据不足一行，需要判断缓冲区的可读数据长度，如果很长但不足一行，就是有问题的
                if (buf->ReadableSize() > MAX_LINE) {
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414;//URI TOO LONG
                    return false;
                }
                //缓冲区中不足一行，但是也不多，等待新数据到来
                return true;
            }
            if (line.size() > MAX_LINE) {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414;//URI TOO LONG
                return false;
            }
            if (line == "\n" || line == "\r\n") {
                break;
            }
            bool ret = ParseHttpHead(line);
            if (ret == false) {
                return false;
            }
        }
        //头部处理完毕，进入正文获取阶段
        _recv_statu = RECV_HTTP_BODY;
        return true;
    }
    bool ParseHttpHead(std::string& line) {
        //key：val\r\nkey：val\r\n..
        if (line.back() == '\n') line.pop_back();//末尾是换行则去掉换行字符
        if (line.back() == '\r') line.pop_back();//末尾是回车则去掉回车字符
        size_t pos = line.find(": ");
        if (pos == std::string::npos) {
            _recv_statu = RECV_HTTP_ERROR;
            _resp_statu = 400;//
            return false;
        }
        std::string key = line.substr(0, pos);  
        std::string val = line.substr(pos + 2);
        _request.SetHeader(key, val);
        return true;
    }
    bool RecvHttpBody(Buffer* buf) {
        if (_recv_statu != RECV_HTTP_BODY) return false;
        //1.获取正文长度
        size_t contetnt_length = _request.ContentLength();
        if (contetnt_length == 0) {
            //没有正文，则请求接收解析完毕
            _recv_statu = RECV_HTTP_OVER;
            return true;
        }
        //2.当前已经接收了多少正文 _request._body
        size_t real_len = contetnt_length - _request._body.size();//实际还需要接收正文的长度
        //3.接收正文放到body中，但是也要考虑当前缓冲区中的数据是否是全部的正文
        //3.1缓冲区中的数据，包含了当前请求的所有正文，则取出所有数据
        if (buf->ReadableSize() >= real_len) {
            _request._body.append(buf->ReadPosition(), real_len);
            buf->MoveReadOffset(real_len);
            _recv_statu = RECV_HTTP_OVER;
            return true;
        }
        //3.2缓冲区中的数据，无法满足当前正文的需要，数据不足，等待新数据到来
        _request._body.append(buf->ReadPosition(), buf->ReadableSize());
        buf->MoveReadOffset(buf->ReadableSize());
        return true;
    }
public:
    HttpContext():_resp_statu(200), _recv_statu(RECV_HTTP_LINE) {}
    void ReSet() {
        _resp_statu = 200;
        _recv_statu = RECV_HTTP_LINE;
        _request.ReSet();
    }
    int ResponseStatu() {
        return _resp_statu;
    }
    HttpRecvStatu RecvStatus() {
        return _recv_statu;
    }
    HttpRequest& Request() {
        return _request;
    }
    //接收并解析Http请求
    void RecvHttpRequest(Buffer* buf) {
        //不同的状态做不同的事情，但是这里不要break，因为处理完请求行后，应该立即处理头部，而不是等待新数据
        switch (_recv_statu) {
            case RECV_HTTP_LINE:  RecvHttpLine(buf);
            case RECV_HTTP_HEAD:  RecvHttpHead(buf);
            case RECV_HTTP_BODY: RecvHttpBody(buf);
        }
        return;
    }
};

class HttpServer {
private:
    using Handler = std::function<void(const HttpRequest&, HttpResponse*)>;
    using Handlers = std::vector<std::pair<std::regex, Handler>>;
    Handlers _get_route;
    Handlers _post_route;
    Handlers _put_route;
    Handlers _delete_route;
    std::string _basedir;//静态资源根目录
    TcpServer _server;
private:
    void ErrorHandler(HttpRequest& req, HttpResponse* rsp) {
       //1. 组织一个错误展示页面
        std::string body;
        body += "<html>";
        body += "<head>";
        body += "<meta http-equiv='Content-Type' content='text/html;charset=utf-8'>";
        body += "</head>";
        body += "<body>";
        body += "<h1>";
        body += std::to_string(rsp->_statu);
        body += " ";
        body += Util::StatuDesc(rsp->_statu);
        body += "</h1>";
        body += "</body>";
        body += "</html>";
        //2. 将页面数据，当作响应正文，放入rsp中
        rsp->SetContent(body, "text/html");
    }
    //将HttpResponse中的要素按照http协议格式进行组织，发送
    void WriteResponse(const PtrConnection& conn, HttpRequest& req, HttpResponse& rsp) {
        //1. 先完善头部字段
        if (req.Close() == true) {
            rsp.SetHeader("Connection", "close");
        }else {
            rsp.SetHeader("Connection", "keep-alive");
        }
        if (rsp._body.empty() == false && rsp.HasHeader("Content-Length") == false) {
            rsp.SetHeader("Content-Length", std::to_string(rsp._body.size()));
        }
        if (rsp._body.empty() == false && rsp.HasHeader("Content-Type") == false) {
            rsp.SetHeader("Content-Type", "application/octet-stream");
        }
        if (rsp._redirect_flag == true) {
            rsp.SetHeader("Location", rsp._redirct_url);
        }
        //2. 将rsp中的要素，按照http协议格式进行组织
        std::stringstream rsp_str;
        rsp_str << req._version << " " << std::to_string(rsp._statu) << " " << Util::StatuDesc(rsp._statu) << "\r\n";
        for (auto& head : rsp._headers) {
            rsp_str << head.first << ":" << head.second << "\r\n";
        }
        rsp_str << "/r/n";
        rsp_str << rsp._body;
        //3. 发送数据
        conn->Send(rsp_str.str().c_str(), rsp_str.str().size());
    }
    bool IsFileHandler(HttpRequest& req) {
        //1. 必须设置了静态资源目录
        if (_basedir.empty()) {
            return false;
        }
        //2. 请求方法必须是GET / HEAD请求方法
        if (req._method != "GET" && req._method != "HEAD") {
            return false;
        }
        //3. 请求的资源路径必须是一个合法路径
        if (Util::ValidPath(req._path) == false) {
            return false;
        }
        //4. 请求的资源必须存在，且是一个普通文件
        // 有一种情况比较特殊  纯粹的相对根目录:/，/image/ 这种情况给后边追加一个index。html
        // index.html   /image/a.png
        // 不要忘记前缀的相对根目录 /image/a.png -> ./wwwroot/image/a.png
        std::string req_path = _basedir + req._path;//为了避免直接修改请求的资源路径，因此定义一个临时对象
        if (req._path.back() == '/') {
            req_path += "index.html";
        }
        // index.html /image/a.png
        if (Util::IsRegular(req_path) == false) {
            return false;
        }
        return true;
    }
    //静态资源请求 --- 将静态资源文件中的数据读取出来，放到rsp的_body中，并设置mime
    void FileHandler(HttpRequest& req, HttpResponse* rsp) {
        std::string req_path = _basedir + req._path;
        if (req._path.back() == '/')  {
            req_path += "index.html";
        }
        bool ret = Util::ReadFile(req_path, &rsp->_body);
        if (ret == false) {
            return;
        }
        std::string mime = Util::ExtMime(req_path);
        rsp->SetHeader("Content-Type", mime);
        return;
    }
    //功能性请求的分类处理
    void Dispatcher(HttpRequest& req, HttpResponse* rsp, Handlers& handlers) {
        //在对应请求方法的路由表中，查找是否有对应的资源请求的处理函数，有则调用 没有则返回404
        //思想：路由表存储的是键值对， -- 正则表达式 & 处理函数
        //使用正则表达式，对请求的资源路径进行正则匹配，匹配成功就使用对应函数进行处理
        // /numbers/(\d+)     /numbers/12345
        for (auto& handler : handlers) {
            const std::regex& re = handler.first;
            const Handler& functor = handler.second;
            bool ret = std::regex_match(req._path, req._matches, re);
            if (ret == false) {
                continue;
            }
            return functor(req, rsp);//传入请求信息，和空的rsp，执行处理函数
        }
        rsp->_statu = 404;
    }
    void Route(HttpRequest& req, HttpResponse* rsp) {
        //1.对请求进行分辨，是一个静态资源请求，还是一个功能性请求
        // 静态资源请求，则进行静态资源的处理
        // 功能性请求需要通过几个请求路由表来确定是否有处理函数
        // 既不是静态资源请求，也不没有设置对应的功能性请求处理函数，就返回404，
        if (IsFileHandler(req) == true) {
            //是一个静态资源请求，进行静态资源请求的处理
            return FileHandler(req, rsp);
        }
        if (req._method == "GET" || req._method == "HEAD") {
            return Dispatcher(req, rsp, _get_route);
        }else if (req._method == "POST") {
            return Dispatcher(req, rsp, _post_route);
        }else if (req._method == "PUT") {
            return Dispatcher(req, rsp, _put_route);
        }else if (req._method == "DELETE") {
            return Dispatcher(req, rsp, _delete_route);
        }
        else {
            rsp->_statu = 405; // METHOD NOT ALLOWED
            return;
        }
    }
    //设置上下文
    void OnConnected(const PtrConnection& conn) {
        conn->SetContext(HttpContext());
        DBG_LOG("NEW CONNECTION %p", conn.get());
    }
    //缓冲区数据解析 + 处理
    void OnMessage(const PtrConnection& conn, Buffer* buffer) {
        while(buffer->ReadableSize() > 0){
            //1. 获取上下文
            HttpContext *context = conn->GetContext()->get<HttpContext>();
            //2. 通过上下文对缓冲区数据进行解析，得到HttpRequest对象
            //  1. 如果缓冲区的数据解析出错，就直接回复出错响应
            //  2. 如果解析正常，且请求已经获取完毕，才开始去进行处理
            context->RecvHttpRequest(buffer);
            HttpRequest &req = context->Request();
            HttpResponse rsp(context->ResponseStatu());
            if (context->ResponseStatu() >= 400) {
                //进行错误响应，关闭连接
                ErrorHandler(req, &rsp);//填充一个错误显示页面数据到rsp中
                WriteResponse(conn, req, rsp);//组织响应发送给客户端
                context->ReSet();
                buffer->MoveReadOffset(buffer->ReadableSize());//出错了就把缓冲区数据清空
                conn->Shutdown();//关闭连接
                return;
            }
            if (context->RecvStatus() != RECV_HTTP_OVER) {
                //当前请求还没有接收完整,则退出，等新数据到来再重新继续处理
                return;
            }
            //3. 请求路由 + 业务处理
            Route(req, &rsp);
            //4. 对HttpResponse进行组织发送
            WriteResponse(conn, req, rsp);
            //5. 重置上下文
            context->ReSet();
            //6. 根据长短连接判断是否关闭连接或者继续处理
            if (rsp.Close() == true) conn->Shutdown();//短链接则直接关闭
        }
        return;
    }
public:
    HttpServer(int port, int timeout = DEFAULT_TIMEOUT):_server(port) {
        _server.EnableInactiveRelease(timeout);
        _server.SetConnectedCallback(std::bind(&HttpServer::OnConnected, this, std::placeholders::_1));
        _server.SetMessageCallback(std::bind(&HttpServer::OnMessage, this, std::placeholders::_1, std::placeholders::_2));
    }
    void SetBaseDir(const std::string& path) {
        assert(Util::IsDirctory(path) == true);
        _basedir = path;
    }
    /*设置/添加，请求(正则表达式)与处理函数的映射关系*/
    void Get(const std::string& pattern, const Handler& handler) {
        _get_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void Post(const std::string& pattern, const Handler& handler) {
        _post_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void Put(const std::string& pattern, const Handler& handler) {
        _put_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void Delete(const std::string& pattern, const Handler& handler) {
        _delete_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void SetThreadCount(int count) {
        _server.SetThreadCount(count);
    }
    void Listen() {
        _server.Start();
    }
};
